Engineered Explosives [Ultimate Masters] Prophecy Promos you may cast the copy

you may cast the copy without paying its mana cost

/ With dragon blade he took each pass by force

Set: Scars of Mirrodin Type: Artifact Creature — Golem Rarity: Mythic Cost: {8} Your life total can't change

others follow

Sacrifice Powder Keg: Destroy each artifact and creature with converted mana cost equal to the number of fuse counters on Powder Keg

Engineered Explosives [Ultimate Masters] Prophecy Promos you may cast the copySet: Ultimate Masters Type: Artifact Rarity: Rare Cost: {X} Sunburst (This enters the battlefield with a charge counter on it for each color of mana spent to cast it.) {2}, Sacrifice Engineered Explosives: Destroy each nonland permanent with converted mana cost equal to the number of charge counters on Engineered Explosives.